Field test unit for a gas turbine fuel injection system

ABSTRACT

A unit is disclosed for field testing the nozzle manifold and fuel starting nozzles of a gas turbine engine. A portable case has a tank that is filled with fuel and pressurized to a predetermined level. The output of the tank is connected to the engine fuel nozzle manifold to test fuel distribution from the main nozzles. The engine starting nozzles are placed on a protractor nozzle support assembly to determine visually their spray pattern.

United States Patent Maresca et a1.

1 51 July 25, 1972 i [54] FIELD TEST UNIT FOR A GAS TURBINE FUELINJECTION SYSTEM [72] Inventors: Neal .1. Maresca, San Francisco,Calif.;

Orrin J. Winton, Bridgeport, Conn.

[73] Assignee: Avco Corporation, Stratford, Conn.

[22] Filed: Feb. 16, 1971 21 Appl. No.: 115,185

52 u.s.c1. ..73/ll9A, 73/168 51 1m.c1. ..G0lml5/00 5s FieldoiSearch...73/1l9A, 168,3;222/399 [56] References Cited UNITED STATES PATENTS2/1960 Schroeder et a1 ..73/l68 1,770,033 7/1930 Hanson ..222/3993,449,948 6/1969 ...73/1 19 A 3,164,012 1/1965 73/119A 2,629,255 2/195373/119 A Primary Examiner-Jerry W. Myracle Altorney-Charles M. Hogan andGary M. Gron 57] ABSTRACT A unit is disclosed for field testing thenozzle manifold and fuel starting nozzles of a gas turbine engine. Aportable case has a tank that is filled with fuel and pressurized to apredetermined level. The output of the tank is connected to the enginefuel nozzle manifold to test fuel distribution from the main nozzles.The engine starting nozzles are placed on a protractor nozzle supportassembly to determine visually their spray pattern.

1 Claim, 2 Drawing Figures Patented July 25, 1972 NEAL J. MARESCA ORRINJ. WINTON 9''. %W' AT TORNEYS FIELD TEST UNIT FOR A GAS TURBINE FUELINJECTION SYSTEM The present invention relates to the testing of gasturbine engines and more particularly to the fuel systems used in thistype of engine.

The gas turbine engine from its very inception has been a highlycomplicated machine requiring sophisticated maintenance procedures. Theneed for complicated instrumentation and special tooling requires thatengines be sent to major service and overhaul facilities, therebysubstantially increasing the time and expense of engine maintenance.This has been particularly true of gas turbine fuel systems where themany conduits, nozzles and controls need to be disassembled and testedwith bench units to determine their performance.

Accordingly, it is an object of the present invention to enable thequick, efiicient and effective testing of the fuel system of a gasturbine engine in the field.

These objects are achieved by a field test apparatus comprising aportable case which has in it a component for supplying a source of fuelat a predetermined sufficient pressure to cause flow through thecomponents of the fuel injection system. A conduit assembly extendingfrom the fuel supply component can be connected to an engine main nozzlemanifold or a fuel starting nozzle so that their flow characteristicscan be tested.

The above and other related objects and features of the presentinvention will be apparent from a reading of the description of thedisclosure shown in the accompanying drawing and the novelty thereofpointed out in the appended claims.

In the drawing:

FIG. 1 is a plan view of a field test unit embodying the presentinvention, along with several gas turbine engine fuel system componentsthat may be tested by the unit;

FIG. 2 is a section view of the field test unit shown in FIG. 1, taken2--2 lines 2-2 of FIG. 1.

Referring now to FIGS. 1 and 2 there is shown a field test unitcomprising a portable case which is used to house the components of thefield test unit. The unit is shown in its test condition in FIG. 1 butfor transport conditions has a suitable cover (not shown) to protect thecomponents of the unit.

The test unit has a series of pressure gauges 12 mounted to a cover 14on case 10. The gauges are connected by conduits (not shown) tocouplings 16 extending from cover 14. The couplings are connected tovarious equipment in the engine to enable a determination of theirperformance, such as: the pressure output of a fuel pump; the output ofa hydraulic pump; or the pressure required to display a particularactuating device. These items are mentioned only to indicate that thecase 10 may incorporate testing equipment other than the fuel injectiontesting apparatus particularly described below.

The apparatus for testing the fuel system components of the gas turbineengine includes a tank 18 formed by a cylinder 20 having a first endplate 22 and a second end plate 24. The end 22, 24 22,24 form aninterior chamber 26. A valve housing 28 is threaded into opening 30 inend plate 24. A longitudinal passageway 32 extends through housing 28and opens into the interior chamber 26. A pair of passages 34 and 36extend at right angles from passage 32. A removable cap 38 is providedover the end of passageway 34 to permit the placing of fuel into chamber26 via passage 34. A valve 40 is mounted over the end of passageway 36.Valve 40 permits pressurization of chamber 26 by connecting apressurizing line to valve 40 and twisting it to an open position. Thevalve 40 is twisted to a closed position before the pressurizing line isremoved from valve 40 to hold the tank pressure. A suitable valve forthis purpose is marketed by the Schrader Division of the ScovillManufacturing Company, Nashville, Tennessee, under the part designationNo. 798, also MS 28889-1.

A conduit 42 is spaced from the walls of and extends throughlongitudinal passage 32 from a fitting 44 in an outer wall of housing 28and is bent to provide an inlet 46 in the lower portion of chamber 26. Acoupling 48 connected to fitting 44 has a conduit 50 which leads to aT-connection 60.

A pressure release valve 52 and an operator manipulated flow controlvalve 54 are interposed in conduit 50. Flow through valve 54 ispermitted or blocked by twisting an operator manipulated knob 56. A fuelfilter 58 is downstream of the flow control valve 54. A conduit assembly88 extends from conduit 50 downstream of the filter 58 to a pressuregauge 90.

A conduit 62 extends from one branch of the T connector 60 to an outletconnector 64. Fitting 64 is adapted to receive a flexible conduit 92which extends to a main fuel nozzle manifold 94 having a series ofnozzles 96 connected to it. When the main fuel manifold is not beingtested a cap 66 is provided, as shown in FIG. 2.

A second conduit 68 extends from the T connector 60 to a nozzle supportunit 70 which comprises a generally L-shaped base 72 and an extensionconduit 74 leading to a fitting 76 that receives a fuel starting nozzle78, as shown in FIG. 1. When a starting nozzle is not in place a cap 80is threaded onto element 76, as shown in FIG. 2.

The spray pattern of the starting nozzle 78 is detennined by aprotractor having exterior diverging sides 102. The angle 0 that thesides 102 make with one another is selected to coincide with the spraypattern of a properly functioning nozzle 78. Protractor 100 is securedby screws 104 to an arm 106. Arm 106 is slidably received in a passage108 in a mounting block 110 secured to cover 14 by screws 112. A setscrew 114 enables the position of arm 106 to be adjusted.

A gas turbine engine fuel system is tested using the field testapparatus in the following manner. Cap 38 is removed to uncover passage34 and chamber 26 is :filled with a sufiicient amount of fuel. Cap 38 isreplaced over passage 34 and an air pressure line (not shown) isconnected to the valve 40 with caps 66 and 80 on connectors 64 and 76,respectively, and flow control valve 54 open. The valve 40 is twisted toan open position and the tank is pressurized to a level which issufficient to produce flow through the fuel injection components to betested.

This level is generally below the normal operating pressures of thepresent fuel system but it is more than sufficient to produce uniformflow in the manifold and the nozzles. It has been found that pressuresof around 100 p.s.i. provide quite acceptable results. Once the pressurein chamber 26 has reached the predetermined level, as observed on gauge90, the valve at 40 is twisted to a closed position and the airpressurizing line is removed from valve 40. The knob 56 on valve 54 istwisted to a closed position and either the starting nozzle or the nonlemanifold is tested.

Assuming that the fuel manifold is tested first, the cap 66 is removedfrom fitting 64 and the flexible line 92 connected. The fuel nozzlemanifold which for most engines is readily removable from the engine asa unit, is placed in a position to be observed by the operator of theequipment. The knob 56 on valve 54 is opened to permit flow through thenozzle manifold 94 and the distribution and performance of flow throughthe nozzles 96 is visually determined. It has been found that fuelnozzle clogging can be quickly spotted using this technique.

Once this operation has been completed, valve 54 is closed, conduit 92removed and cap 66 placed on fitting 64. After this is done, cap 80 isremoved from fitting 76 and a starting nozzle 78, which is also easilyremoved from most engines, is threaded onto fitting 76. The protractor100 and its supporting arm 106 are adjusted by means of the set screw114 to line up the point of convergence of the sides 102 at the nozzleopening. After this is done the knob 56 is manipulated to per mit flowthrough the nozzle assembly. The spray pattern from the noale isvisually determined using the sides 102. If the pattern just covers theprotractor 100 it is properly functioning. A spray cone angle outside orinside the sides 102 indicates plugging or another malfunction. Whenthis test has been completed valve 54 is closed, the nozzle 78 removedand cap 80 placed on fitting 76.

When the field test of the fuel injection equipment has been completedthe protractor 100 and supporting arm 106, ex-

tending outboard of the case 10, are removed from passage 108 andinserted from the opposite end of passage 108 so that the protractor 100and arm 106 are entirely contained within the bounds of case 10, asshown by the phantom lines in FIG.

novel and desired to be secured by Letters Patent of the United Statesis:

1. Apparatus for field testing the main nozzle manifold and the fuelstarting nozzle of a fuel injection system of a gas tur- I. In likemanner the nozzle support fitting 76 and arm 74 are 5 bi engine, saidapparatus comprising:

pivoted to the phantom position of FIG. 1 so that they are completelycontained in the limits of case 10. The unit is thus ready for transportuntil such time as the fuel injection components are to be tested whenthe above procedure would be reversed.

The above unit provides a highly eflective and rapid means of fieldtesting the most important fuel injection components of a gas turbineengine in the field. The use of the pressurized tank enables a highlyaccurate and repeatable fuel flow and pressure in order to provideaccurate results. The starting nozzle support and the protractor arequickly positioned outboard of the case so that the fuel thus dischargedwill not spill onto the unit. However, these units are quickly placed ina transport position to enable a compact unit for transport.

While the preferred embodiment of the present invention has beendescribed, it is apparent to those skilled in the art that othermodifications may be performed without departing from its spirit andscope.

Having thus described the invention, what is claimed as a portable case;

a tank mounted within said case;

a filling and distributing means connected to said tank for permittingfilling of said tank with fuel and pressurizing it; and

means for controlling fuel flow from said tank;

a conduit extending from said flow control means and having first andsecond branch outlets;

caps releasably secured to said branch outlets for selectivelypermitting flow to said engine main nozzle manifold and to a fuelstarting nozzle, whereby the flow characteristics of said assemblies maybe tested;

means on said case for supporting a fuel starting nozzle at the end ofsaid first branch outlet; and

means releasably supported adjacent said nozzle support means and havingdivergent sides for determining visually the spray pattern of saidstarting nozzle.

OI t i it t

